Hi, So apparently when we had our furnace serviced a month ago, the repair man left the fuel petcock for one of our two oil tanks in the off position. As a result, the furnace ran dry after using the oil up in one tank. Normally, it draws from both tanks at once. Today, I got an oil delivery, bled the air out of the line and now the furnace is up and running. However, the oil delivery we got filled one tank, but didn't cross over to the other. Normally the two tanks balance when filled, because they have a common fill pipe, and the furnace draws oil from both. What's the deal? How come the oil isn't balancing between the two tanks? How do I get it back to normal? I dont know if it was necessary, but I shut the petcock off for the empty one so it doesn't suck more air.